Containers for foods or beverages (foodstuff) are required to be sterilized on inner and outer surfaces thereof. As a conventional sterilization method, a method using an aqueous hydrogen peroxide or a chemical has been known. However, there are some disadvantages that the aqueous hydrogen peroxide or chemical is likely to remain, so that the development of substitute techniques has been studied.
For example, Patent Publication 1 discloses a method including generating a plasma jet using discharge in a fluid, contacting a surface to be treated with the plasma jet, and carrying out sterilization (disinfection) by way of energy transfer from the plasma jet to the surfaces. The plasma jet as used herein is generated by air discharge in a process gas containing oxygen, preferably the air.
In addition, Patent Publication 2 discloses a method of carrying out deodorization sterilization in a refrigerator using a plasma device that generates plasma to produce ozone or reactive species. More specifically, sterilization of the deposited bacteria is carried out by generating plasma in the gap of the set electrodes to deodorize, and releasing ozone or reactive species produced in the plasma by ventilation.